Sense of Scale

This provides a much needed sense of scale when looking at the Bok 2.3m telescope. That's 2.3 meters, or 230 centimeters...which means the primary mirror on the Bok telescope is larger in diameter than I am tall. We have the telescope tipped over to (almost) it's limit in order to flll the camera up with liquid nitrogen. Also in the image are the mirror cover (next to me) and the instrument we used (called 90prime) in the middle of the black ring

This provides a much needed sense of scale when looking at the Bok 2.3m telescope. That’s 2.3 meters, or 230 centimeters…which means the primary mirror on the Bok telescope is larger in diameter than I am tall. I could lay down comfortably on the mirror and fit easily (…but I won’t do that…). We have the telescope tipped over to (almost) its limit in order to flll the camera up with liquid nitrogen (the camera is that big black thing inside the black ring). Also in the picture is the mirror cover, the pyramid-like structure right next to me.

The Bok 2.3m in Action

Having fun with a GoPro Hero3 camera. Before any night time observing occurs, the telescope and instrument require set up, and calibration images need to be taken. We arrive about an hour before sunset (which was roughly 6:15pm local time during the week I was there) to start setup. First we fill the instrument’s dewar with liquid nitrogen to keep the instrument cold. Then we do calibration images. This time-lapse shows the hour of set up and calibration we did on one of our observing nights.

I couldn’t capture a time-lapse of the whole evening because the GoPro doesn’t work well at night. GoPro’s are designed for day time use. Ah wells.

Inside the Bok

Here's me standing under the Bok 90inch (that's 2.3 meters for you metric peoples).

Here’s me standing under the Bok 90inch (that’s 2.3 meters for you metric peoples). The instrument we’re using is called 90prime, which is located at the top of the ‘scope. More on that below.

The control of the Bok 2.3m. On the left are the computers that control the instrument (i.e., filters, exposing), on the right is the telescope operations (i.e., slewing to new positions, moving dome, etc.).

The control room for the Bok 2.3m. On the left are the computers that control the instrument (i.e., filters, exposing), on the right is the telescope operations (i.e., slewing to new positions, moving dome, etc.).

We had a little trouble with our filter wheel on the second night of our observing run. The filter wheel is a mechanical wheel that holds different filters designed to let only certain ranges of light to pass through. Due to the problems we had to tip the telescope over to get at the instrument.

We had a little trouble with our filter wheel on the second night of our observing run. The filter wheel is a mechanical wheel built into 90prime that holds different filters; the filters are designed to let only certain ranges of light to pass through. Since 90prime is located at the top of the scope, we had to tip the telescope over to get at the instrument.

Mike, staff at the Steward Observatory, is helping us diagnose and fix our filter wheel issue. He's working on the instrument. The instrument, 90prime, sits at the prime focus of the telescope, and is about as tall as I am.

Mike, staff at the Steward Observatory, is helping us diagnose and fix our filter wheel issue. The image shows him working on the instrument. 90prime sits at the prime focus of the telescope (which is why we have to tip the telescope on its side to work on it). 90prime is an imager with a field of view of 1 square degree. To get an idea of the size, 1 square degree would be able to fit 4 full Moons in an a given image, since the Moon is about 0.5 degrees in angular size. Also note in the image we’re looking down at the 2.3 meter mirror. The star-like pattern is the opened mirror cover. When we want to protect the mirror we close the mirror cover.

The telescope is pointed at the white screen bathed in light from the halogen's below. This is what astronomer's call 'flat fielding.' When you build a CCD, not every pixel is going to respond the exact same way to light. In order to calibrate for this, you shine every pixel with the same amount of light, which then tells you how each pixel behaves differently. You can then 'flatten' the field using that image. Also looks spooky.

The telescope is pointed at the white screen bathed in light from the halogen bulbs below. This is what astronomer’s call ‘flat fielding.’ When you build a CCD, not every pixel is going to respond the exact same way to light. In order to calibrate for this, you shine every pixel with the same amount of light, which then tells you how each pixel behaves differently. You can then ‘flatten’ the field using that image. Also…. it looks spooky.

Ready and waiting for twilight to end. The dome has been opened and the scope is ready to start.

Ready and waiting for twilight to end. The dome has been opened and the scope is ready to start.

Outside the Bok

Haha. the Bok and the Bike. The Bok 90inch telescope towering over my tiny motorcycle.

Haha. the Bok and the Bike. The Bok 90inch telescope towering over my tiny motorcycle. The hand railing you see about 2/3rds of the way up the structure is known as the ‘Bok Walk.’ The white donut to the bottom right is the original cement mirror blank for the Bok. Since most telescopes are actually built before their mirror is completed, ‘mirror blanks’ are created in the exact dimension/weight of the mirror-to-be. The blank is installed so that the telescope can be balanced in advance of the mirror arriving. After it is no longer needed, the blank can become an exhibit piece.

The hatch leading from the telescope out onto the Bok Walk. It offers a fantastic view.

The hatch leading from the telescope out onto the Bok Walk. It offers a fantastic view.

This is taken from the Bok Walk looking over the road coming up the mountain.

This is taken from the Bok Walk looking over the road coming up the mountain.

The Bok and the Mayall telescopes. The Mayall 4m is one of the more famous telescopes on the mountain. It is the highest elevated telescope on the mountain (2120m), which is actually taller than the summit of Kitt Peak itself (2098m).

The Bok (left) and the Mayall (right) telescopes. The Mayall 4m is one of the more famous telescopes on the mountain. It is the highest elevated telescope at 2120m, which is actually taller than the summit of Kitt Peak itself (2098m).

test

[Roll mouse over to animate]. Heading to dinner before the night’s observing run I took a look back at the Bok telescope, among others. These ‘scopes are on the north-most part of Kitt Peak. This is shot is taken looking in the North direction.

goodview

[Roll mouse over to animate]. This is the view from the Bok Walk at sunset looking south over the whole of Kitt Peak (the Sun is setting off to the right). If you roll your mouse over the image you’ll see the location from which I took these images.

The Steward Observatory Kitt Peak Observing Station, erected in 1962.

The Steward Observatory Kitt Peak Observing Station, erected in 1962.